Can you not record your activity items with a new “type” and then use the “action=[typename]” filter in the loop to filter on only that type? Also, in the previous thread, editing the JS is a bad idea, you should be able to pass the extra information via the “extras” parameter in the AJAX request. You’ll need to set this in your own plugin JS. This needs to be documented, but there are a couple of plugins doing it – I think bp-links is.